Reference for Menachot 194:2
ר' מאיר סבר זהו באמה בת חמשה הא כל אמות כלים באמה בת שש ורבי יהודה סבר כזה יהו כל אמות כלים
'The bottom shall be a cubit' refers to the base [of the altar 'and a cubit the breadth' refers to the sobeb; 'and the border thereof by the edge thereof round about a span refers to the horns;<span class="x" onmousemove="('comment',' These were blocks measuring one cubit each side which were placed upon the four corners of the altar. The measurement of a span stated in this verse in regard to the horns is explained as referring to the distance from the middle of each surface in every direction, i.e., the four quarters of every surface each measured a span by a span, therefore the whole of the surface was a cubit-square.');"><sup>3</sup></span> 'and this shall be the base of the altar' refers to the golden altar.<span class="x" onmousemove="('comment',' I.e., the golden altar was also measured by the cubit of five handbreadths.');"><sup>4</sup></span>